Circuit assembly

ABSTRACT

In a telephone repeater assembly, a plurality of fasteners is maintained in a self-supporting array by a framework of attached runners. The fasteners are aligned with and joined to a mating part in a pattern which substantially corresponds to the array. Flexibility of the runners permits minor adjustments to the positions of the fasteners in the array to align the fasteners precisely to the pattern on the mating part. Handling the fasteners in such an array facilitates assembly of the fasteners into the mating part. A circuit board is mounted to such part with one side thereof contiguous to the array of fasteners. The board has a plurality of apertures in addition to its mounting holes for the insertion of wide-headed contact screws. The screws are retained by the fasteners. Upon full insertion of the contact screws the head of the screws bridges a gap between two separate conductors on the board and establishes electrical continuity therebetween.

United States Patent Cagle et a].

CIRCUIT ASSEMBLY Inventors: Albert W. Cagle, Raytown; Wayne E. Greer,Independence; Wilbur J. Weight, Lees Summit, all of Mo.

Western Electric Co., Inc., New York, NY.

Filed: May 6, 1974 Appl. No.: 467,360

Related US. Application Data Division of Ser. No. 228,152, Feb. 22,1972.

Assignee:

References Cited UNITED STATES PATENTS 12/1960 DuVal, Jr. et al 317 101CE 12/1969 Ljungdell et a1 317/101 CE [451 May 13, 1975 PrimaryExaminer-Darre11 L. Clay Attorney, Agent, or FirmW. O. Schellin [57]ABSTRACT In a telephone repeater assembly, a plurality of fasteners ismaintained in a self-supporting array by a framework of attachedrunners. The fasteners are aligned with and joined to a mating part in apattern which substantially corresponds to the array. Flexibility of therunners permits minor adjustments to the positions of the fasteners inthe array to align the fasteners precisely to the pattern on the matingpart. Handling the fasteners in such an array facilitates assembly ofthe fasteners into the mating part. A circuit board is mounted to suchpart with one side thereof contiguous to the array of fasteners. Theboard has a plurality of apertures in addition to its mounting holes forthe insertion of wide-headed contact screws. The screws are retained bythe fasteners. Upon full insertion of the contact screws the head of thescrews bridges a gap between two separate conductors on the board andestablishes electrical continuity therebetween.

5 Claims, 3 Drawing Figures CIRCUIT ASSEMBLY This is a division ofApplication Ser. No. 228,152 filed Feb. 22, 1972, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to expeditiously handling a plurality of fasteners and, moreparticularly, to a structure of fasteners for insertion into a base andto an assembly including these elements.

2. Description of the Prior Art Mechanical devices using a large numberof fasteners often present a problem in their assembly in that therepetitive operation of applying the fasteners is tedious, timeconsuming and, consequently, expensive. Some devices, fortunately,permit automatic or semiautomatic insertion of fasteners.

Other devices do not readily lend themselves to being assembled byautomatic machinery. A few of the latter devices present a compoundedproblem, in that both male and female fasteners are required in theassembly.

For example, a particular assembly includes a printed circuit board anda plurality of fasteners. The printed circuit board has a repetitivepattern of printed conductor terminals on opposite sides of an aperturein the board. Upon insertion of a screw into the aperture, the head ofthe screw bridges the gap between the conductor terminals to establishcontact between the conductors. A lock nut on the reverse side of theboard retains the screw in contact with the terminals. Because of thenumber of these circuit connections in the board, its assembly becomesquite cumbersome.

A known fastening device has limitations which make it inapplicable foruse in such a printed circuit board assembly. This known device combinesseveral pairs of yieldable tongues formed in an elongated metal stripfor receiving a plurality of screws. The pairs of tongues are arrangedat certain intervals in the strip to guide the inserted screws intoprecise position with respect to the metal strip. While this deviceguides the inserted screws into the already established positions in thedevice, there is no provision for adjustment of the relative positionsof the tongues by shifting their positions. Such shifting is oftennecessary to accommodate a variation from the established dimensions dueto manufacturing tolerances.

Such lack of provision for adjustment is particularly disadvantageouswhere the fasteners lie in a planar, multidirectional array rather thanin merely a straightline arrangement. In such a case, two-dimensionalvariations are to be expected which require a certain amount ofadjustment to achieve an alignment of the fasteners in the array with amating part. Such an adjustment is not possible according to the priorart.

SUMMARY OF THE INVENTION An object of this invention is, therefore, toexpeditiously handle a plurality of fasteners.

Another object of this invention is to provide a new and improvedstructure of fasteners for insertion into a base and an assemblyincluding these elements.

Another object of the invention is the provision of a structure forinsertion into a plurality of positions in a base that are subject tovariations due to tolerances.

It is another object of the invention to provide a structure offasteners in an array of sufficient rigidity to normally maintain thefasteners in substantially fixed relation to each other, and of aresiliency to permit the shifting of the fasteners with respect to eachother to compensate for misalignment between the fasteners of the arrayand a mating part.

According to these and other objects and advantages discussed in orapparent from this specification, the invention is summarized asfollows:

The handling of a plurality of fasteners to be assembled in a pattern isfacilitated by interconnecting the fasteners into an array correspondingto the pattern and by positioning the array with respect to a matingpart. Deforming the interconnections between the fasteners shifts thepositions of the fasteners relative to each other, such that thefasteners coincide with predetermined positions on the mating art. 4 pAn assembly, according to the invention, comprises a base having aplurality of cavities located according to a defined pattern in onesurface thereof, an array of interconnected fasteners located inaccordance with the defined pattern in the cavities, a circuit boardlocated with one surface thereof contiguous to the fasteners, the othersurface of the board having a plurality of pairs of conductors thereon,and a plurality of screws inserted through the board into the fasteners,the screws adapted to establish electrical continuity between theconductors of each pair of conductors.

BRIEF DESCRIPTION OF THE DRAWING A complete understanding of theinvention can be obtained from the following detailed description of aspecific embodiment of the invention when read in conjunction with theaccompanying drawing, wherein:

FIG. 1 is a perspective view of an array of fasteners according to theinvention;

FIG. 2 is a perspective view of a base into which the array of FIG. 1may be inserted; and

FIG. 3 is a perspective view, partly in section, showing an assembly ofthe array of FIG. I, the base of FIG. 2, a printed circuit board, and athreaded member.

DETAILED DESCRIPTION Referring now to FIG. 1 of the drawing, a structureor fastening device, designated generally by the numeral 10, is shown.The device 10 is comprised of two groups of elements, namely, aplurality of individual retainers or fasteners 11, and interconnectingmembers or runners 12. The runners l2 interconnect the fasteners 11 inan array, designated generally by the numeral 13, as shown in FIG. 1.The runners 12 complete the device 10 to normally retain each of thefasteners 11 in a specified position.

The fasteners 11 are preferably formed 'of a resilient plastic materialsuch as, for example, commercially available nylon or the like. Such amaterial lends itself to economical processes of molding, and exhibits,after molding, a rigidity and resiliency desirable to practice theinvention.

The fasteners 11, of FIG. 1, are comprised of a block of material in theshape of arr-orthogonal prism. An aperture l5 estends through each ofthe fasteners 11. It is possible to form threads in the cylindricalinternal surface 16 of the aperture 15 to receive a threaded male membersuch as, for example, a screw 18 having a head 19. However, thepreferred embodiment of FIG. I does not contemplate such threads.Without the threads the fastener 11 functions as a lock nut. Thus,

the screw 18 when rotatably inserted into the unthreaded apertureplastically deforms the fastener 11 to some extent in forming threads inthe surface 16. Due to the resiliency of the nylon, the material of thefastener 1 1 seizes the threads 19 of the screw 18 to frictionallyresist a rotational movement of such screw. This resistance to rotationgives the fasteners 11 their locking characteristic.

The runners 12 extend between the fasteners 11 to interconnect thefasteners into the desired array 13. Such runners 12 are sufficientlyrigid or stiff for two important purposes: (a) to maintain the fasteners11 in the array 13 in the desired positions with respect to each other;and (b) to render the array 13 selfsupporting. The term self-supporting,as used herein, denotes the ability of the array 13 to maintainsubstantially its shape and the fasteners 11 in a given plane withoutflexing when supported at any single point of the array.

The runners 12 also are sufficiently flexible in response to appliedforces to permit an adjustment of the relative positions of thefasteners 11. Such an adjustment includes shifting selected ones of thefasteners 11 of the array 13 slightly with respect to the otherfasteners 11, such that the array 13 actually becomes distorted from itsnormal shape.

Thus, the runners 12 satisfy two requirements: (I) they are rigid to theextent of maintaining the fasteners in the array 13 and to the extent ofbeing, in combination with the fasteners 11, self-supporting, and (2)they are also flexible in response to forces to permit a distortion ofthe normal array 13 for realigning the fasteners 11. Proper selection ofthe cross-sectional area of each of the runners 12 depends, of course,upon a desired balance between rigidity and elasticity or flexibility tooptimize the handling and adjustment characteristics of the device 10.

In a particular example of the device 10 shown in FIG. 1 the materialfor the fasteners 11 and the runners 12 has been chosen to be acommercial, glass-filled nylon. The center distances between twoadjacent fasteners 11 in this particular array 13 vary betweenfivesixteenth of an inch and one and one-quarter inch. Under theseconditions a cross-sectional area 21 of the runners conveniently has asemi-circular shape, approximately one-sixteenth of an inch in diameter.As shown in FIG. 1 the runners 12 lie in a single plane and are attachedto the fasteners 11 at one end plane of such fasteners, such that theflat, diametrical surface 22 of the runners 12 lies in the same plane asa square end surface 23 of each of the fasteners 11.

Extending the fasteners 11 in this manner in their total lengthperpendicular to and on one side of the plane of the runners l2facilitates the adjustment of two adjacent ones of the fasteners 11 withrespect to each other. The free ends 24 of the fasteners 11 are movabletowards and away from each other, or they may even be moved in adirection perpendicular to a common axis between such fasteners. Such anadjustment results only in minor flexing of the corresponding runner 12.

FIG. 2 shows a frame or base 25 which contains a number of cavities 26.The cavities 26 are arranged in a desired pattern 27 on centerlinessubstantially coinciding with those of the array 13.

The cavities 26 have a shape similar to, but slightly larger than, thatof the fasteners ill to permit the fasteners 11 to slide into suchcavities 26 once such fasteners are aligned with the correspondingcavities. The difference in size between the cavities 26 and thefasteners 11 is such that a rotational movement of the fasteners 11within such cavities is constrained. However, the larger cavities 26permits some tilting and also some lateral movement of the fastenerswithin the cavities after assembly. This type of movement of thefasteners 11 within the cavities 26 is referred to as floatlng.

While the square end surface 23 is convenient from the manufacturingstandpoint, end surfaces having shapes other than a square areconsidered to be equivalent to the square shape. It is, however,preferred for the fasteners 11 to be orthogonal prisms. When thefasteners 11 are of such prismatic shape, longitudinal corners 29 of thefasteners are adjacent to similar corners 31 of the cavities 26 afterthe fasteners have been inserted, one into each cavity. The resultingkeying action between the fasteners 11 and the corresponding cavities 26prevent the fasteners from rotating within the cavities when a torque isapplied to such fasteners.

The array 13 of fasteners 11 substantially coincides with a pattern 27,of cavities 26 in the base 25. A plurality of channels 32 accommodatesthe runners 12. Typically, the channels 32 are somewhat larger incross-section than the respective runners 12. The amount the channels 32are larger than the runners 12 is determined by deviations from thenormal specified dimensions that can be expected in the manufacture ofthe device 10 and the base 25. In the preferred embodiment the channels32 are larger than the runners 12 by one-thirtysecondth of an inch overthe diametrical dimension of the runners 12.

Preparatory to the insertion of the device 10 into the base 25 thedevice 10 is aligned thereto. Upon such alignment, each of the fasteners11 substantially coincides with one of the cavities 26 in the base 25.Then, the device 10 is inserted as a unit into the base 25.

The normal manufacturing tolerances on both the device 10 and the base25 sometimes necessitate some adjustment to shift some of the fasteners11 in the array 13 before the device is inserted into the base. Ausually slight distortion in some portions of the array 13 ultimatelyresults in the precise alignment of the fasteners 11 with respect tocorresponding ones of the cavities 26 in the base 25.

The position of any one of two fasteners 11 of the array 13 can beadjusted with respect to the other of the two fasteners 11 by flexingthe corresponding interconnecting runner 12 to align the fasteners 11 tothe location of their respective cavities 26. A particular one of therunners 12 may be flexed about an axis parallel to the plane of suchrunner and perpendicular to its length. The resulting flexure of therunner 12, depending on its direction, either increases or decreases thecenter distance between the two respective fasteners 11 at the free ends24 of such fasteners.

In addition to increasing or decreasing such center distance, one of thefasteners 11 may be shifted laterally from a line extending between therespective fastener l1 and one other adjacent fastener 11 of the array13. Such a lateral shift with respect to such line requires acorresponding lateral flexure or a tortional flexure of the runner l2interconnecting the two'adjacent fasteners.

Flexing the runners 12 as described permits each fastener 11 to beprecisely aligned to a corresponding cavity 26 in the base 25. When,subsequent to such an alignment, the device is inserted as a unit intothe base 25 some of the runners 12 will undergo an additional strain toadjust to the aligned positions of the inserted fasteners 11.

FIG. 3 shows a section of an assembly 33 including the base 25 incombination with a circuit board 34. This assembly 33 is a particularexample of an apparatus which is improved by the use of the invention.

In the prior art, a particular telephone repeater circuit (not shown)utilizes a base, similar to the base 25 'in combination with the circuitboard 34. The base 25 for the repeater circuit traditionally has had aplurality of cavities 26 for accepting a standard lock nut (not shown)in each of the cavities 26. These individual lock nuts are cumbersome toassemble into the respective cavities 26. To use the invention asdescribed, the base 26 is modified to include a plurality of channels 32between selected ones of the cavities 26. The number and location ofthese channels 32 in the base 26 correspond to the number and positionof the runners 12 of the device 10. The addition of the channels 32permits a flush insertion of the device 10 into the base 25 as describedabove.

The circuit board 34 has, in a conventional manner, a component side 36which holds a given number of components 37. Special recesses 41 in thebase 25 accept the components 37 when the board 34 is assembled to thebase 25 with the component side 36 facing the base. When the board 34 isassembled in this manner, a conductor side 42 on the board 34 liesupwardly exposed. A set of oversize holes 43 accept a correspondingnumber of screws 44 to fasten the board 34 to the base 25. FIG. 2 showsa number of threaded portions 45 in the base 25. These threaded portionsare in substantial alignment with the holes 43 in the board 34. Theoversize of the holes 43 with respect to the shank 46 permits a smallamount of lateral adjustment between the base 25 and the board 34 beforethe screws 44 are fastened to position the board.

Paired sets of conductive strips 47 on the conductor side 42 of theboard 34 are normally open electric circuit terminations. The strips 47are positioned on the board 34, such that each pair of the stripsstraddles one of the centers of the cavities 26 in the base 25. A numberof apertures 49 through the board 34 are centered between respectiveones of the paired sets of conductive strips 47 and are also centeredwith respect to the axes of the cavities 26 in the base 25. Each of theapertures 49 corresponds to a different pair of conductive strips 47 andalso to a particular cavity 26.

An improved repeater circuit assembly, as for instance as assembly 33shown in FIG. 3, includes the device 10. The aperture of each of thefasteners 11 of the device 10 in such assembly 33 is aligned with acorresponding one of the apertures 49 through the circuit board 34. Thealignment facilitates inserting one of the screws l8 through each of theapertures 49 into one of the underlying fasteners 11 of the device 10.

The fasteners 11 lock the inserted screws 18 in place to preventunintentional motion of such screws with respect to the fasteners 11regardless of the amount of engagement of the screws 18 with respect tothe fasteners 11. For example, a screw 18 partially inserted into one ofthe fasteners 11 remains secured to such fastener 11 just as anotherscrew 18 fully inserted into another one of the fasteners 11 remainssecured to that fastener l 1.

The head 19 of such fully inserted screw 18 contacts the circuit board34, and particularly the pair of conductive strips 47 straddling theaperture 49 associated with the screw 18. The head 19 of the screw 18when tightened against the pair of conductive strips 47 bridges the gap51 between such strips 47 to establish electrical connection between thestrips 47.

Circuit boards 47 inherently may have some surface irregularities as forinstance a raised portion 52 on one of the pair of conductive strips 47shown in FIG. 3. Without adjustment to the position of the associatedfastener 11, the head 19 of the screw 18 being inserted therein isstopped by the raised portion 52 on the one strip 47. Consequently thehead 19 is prevented from establishing contact with the other strip 47,and the pair of conductive strips 47 do not become electricallyconnected after full insertion of the screw 18 into the associatedfastener 11.

The larger cavities 26 permitting movement or floating of the fasteners1 1 within the cavities after assembly of the fasteners 11 therein avoidsuch non-connecting where the head 19 of one of the screws 18 fails toestablish contact between the associated pair of strips 47 after suchscrew 18 has been fully inserted into one of the fasteners 11. When thehead 19 of a screw 18 inserted into one of the fasteners 11 contacts theraised portion 52 on the strip 47 the fastener 11 floats within itscavity 26 to permit the screw 18 to tilt from its normal axis ofinsertion. This floating causes the head 19 to tilt with the screw 18 toestablish-contact between the raised portion 52 on the one strip 47 withthe lower lying second strip 47 of the pair.

The known insulating characteristics of nylon are of significance in theuse of the device 10 in the assembly 33. Each of the pairs of conductivestrips 47 in conjunction with one of the screws 18 is used in thecompleted assembly 33 as a separate, selectively operable switch tofunction independently from the other conductive strips 47 inconjunction with their respective screws 18. The insulatingcharacteristics of the nylon runners 12 maintain the electricalseparation between each of the fasteners 11 and their respective screws18.

The foregoing description of the invention in relation to the circuitboard assembly is for explanatory purposes only and is not to beconstrued as a limitation to the scope of the invention. For example, anarray of fasteners may include a plurality of male fasteners in place ofthe described fasteners 11. Or the fasteners of an array of fastenersmay be arranged in a multi-planar configuration. Many other examples,arrangements and modifications thereof are possible without departingfrom the scope of the invention.

What is claimed is:

1. A circuit board assembly comprising:

a base having a flat surface, a plurality of cavities located accordingto a defined pattern in the flat surface, and a plurality of channelslocated in the plane of the flat surface, each of the channelsconnecting one of the cavities with at least one other adjacent one ofthe cavities;

an array of fasteners comprised of a plurality of apertured blocks, anda plurality of runners interconnecting the blocks into a self-supportingstructure, the runners positioning the blocks substantially according tothe pattern of cavities in the base, each of the blocks occupying one ofthe cavities in the flat surface of the base, the runners beingpositioned within the channels;

a circuit board located with one side thereof contiguous to the flatsurface of the base and to the array of fasteners, the board having (1)a plurality of apertures arranged in a pattern which coincides with thepattern of cavities, the apertures in the board being coaxially alignedwith the apertures of the fasteners located within the cavities, and (2)a circuit conductor pattern on a second side facing away from the base,the conductor pattern including a plurality of conductor pairscorresponding in number to the'apertures through the board, eachconductor pair straddling one of the apertures in the board; and

a plurality of wide-headed contact screws inserted into each of theapertures in the board and extending through the board into lockingengagement with the apertures of the fasteners, the head of each screwadapted to make contact with both conductors of the corresponding pairof conductors for establishing electrical continuity between such pairof conductors.

2. A circuit board assembly according to claim 1, wherein the cavitieshave walls spaced from the surfaces of the blocks, the wallsconstraining rotational movement of the blocks within the cavities whilepermitting tilting or lateral floating of the blocks in response toinserted contact screws tilting upon contact of the heads of such screwswith respective pairs of conductors.

3. An assembly comprising: a base having a plurality of cavities locatedaccording to a defined pattern in one surface thereof; an array offasteners, interconnected by runners into a self-supporting structure,the fasteners located in accordance with the defined pattern in thecavities;

a circuit board located with one surface thereof contiguous to thefasteners, the other surface of the board having a plurality of pairs ofconductors thereon; and

a plurality of screws inserted through the board into the fasteners, thescrews adapted to establish electrical continuity between the conductorsof each pair of conductors.

4. An assembly in accordance with claim 3 wherein the fasteners and therunners are of glass filled nylon and the runners are integrallyattached to respective ones of the fasteners.

5. An assembly in accordance with claim 3, wherein the cavities and thefasteners have a square cross section, and wherein the cavities havewalls spaced from the surfaces of the fasteners, the walls constrainingrotational movement of the fasteners within the cavities whilepermitting tilting or lateral floating of the fasteners within thecavities.

1. A circuit board assembly comprising: a base having a flat surface, aplurality of cavities located according to a defined pattern in the flatsurface, and a plurality of channels located in the plane of the flatsurface, each of the channels connecting one of the cavities with atleast one other adjacent one of the cavities; an array of fastenerscomprised of a plurality of apertured blocks, and a plurality of runnersinterconnecting the blocks into a self-supporting structure, the runnerspositioning the blocks substantially according to the pattern ofcavities in the base, each of the blocks occupying one of the cavitiesin the flat surface of the base, the runners being positioned within thechannels; a circuit board located with one side thereof contiguous tothe flat surface of the base and to the array of fasteners, the boardhaving (1) a plurality of apertures arranged in a pattern whichcoincides with the pattern of cavities, the apertures in the board beingcoaxially aligned with the apertures of the fasteners located within thecavities, and (2) a circuit conductor pattern on a second side facingaway from the base, the conductor pattern including a plurality ofconductor pairs corresponding in number to the apertures through theboard, each conductor pair straddling one of the apertures in the board;and a plurality of wide-headed contact screws inserted into each of theapertures in the board and extending through the board into lockingengagement with the apertures of the fasteners, the head of each screwadapted to make contact with both conductors of the corresponding pairof conductors for establishing electrical continuity between such pairof conductors.
 2. A circuit board assembly according to claim 1, whereinthe cavities have walls spaced from the surfaces of the blocks, thewalls constraining rotational movement of the blocks within the cavitieswhile permitting tilting or lateral floating of the blocks in responseto inserted contact screws tilting upon contact of the heads of suchscrews with respective pairs of conductors.
 3. An assembly comprising: abase having a plurality of cavities located according to a definedpattern in one surface thereof; an array of fasteners, interconnected byrunners into a self-supporting structure, the fasteners located inaccordance with the defined pattern in the cavities; a circuit boardlocated with one surfacE thereof contiguous to the fasteners, the othersurface of the board having a plurality of pairs of conductors thereon;and a plurality of screws inserted through the board into the fasteners,the screws adapted to establish electrical continuity between theconductors of each pair of conductors.
 4. An assembly in accordance withclaim 3 wherein the fasteners and the runners are of glass filled nylonand the runners are integrally attached to respective ones of thefasteners.
 5. An assembly in accordance with claim 3, wherein thecavities and the fasteners have a square cross section, and wherein thecavities have walls spaced from the surfaces of the fasteners, the wallsconstraining rotational movement of the fasteners within the cavitieswhile permitting tilting or lateral floating of the fasteners within thecavities.